221 

y 1 



DEPARTMENT OF COMMERCE 
BUREAU OF FISHERIES 

HUGH M. SMITH, Commissioner 



WATER-POWER DEVELOPMENT IN RELATION 

TO FISHES AND MUSSELS OF 

THE MISSISSIPPI 

By Robert E. Coker 

Director United States Biological Station 
Fairport, Iowa 



APPENDIX VIII TO THE REPORT OF THE U. S. COMMISSIONER 
OF FISHERIES FOR 1913 




Bureau of Fisheries Document No. 805 



.WASHINGTON 

GOVERNMENT PRINTING OFFICE 

1914 



•wqgripfe 



DEPARTMENT OF COMMERCE 

BUREAU OF FISHERIES 

HUGH M. SMITH, Commissioner 



WATER-POWER DEVELOPMENT IN RELATION 

TO FISHES AND MUSSELS OF 

THE MISSISSIPPI 

By Robert E. Coker 

Director United States Biological Station 
Fairport, Iowa 



APPENDIX VIII TO THE REPORT OF THE U. S. COMMISSIONER 
OF FISHERIES FOR 1913 




Bureau of Fisheries Document No. 805 



WASHINGTON 

GOVERNMENT PRINTING OFFICE 

1914 






ADDITIONAL COPIES 

OF THIS PUBLICATION MAY BE PROCURED FROM 

THE SUPERINTENDENT OF DOCUMENTS 

GOVERNMENT PRINTING OFFICE 

WASHINGTON, D. C. 

AT 

10 CENTS PER COPY 
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C. of D. 
.PR 14 (9 5 



, 



WATER-POWER DEVELOPMENT IN RELATION TO 
FISHES AND MUSSELS OF THE MISSISSIPPI 



By Robert E. Coker 

Director United States Biological Station 
Fair port, Iowa 



Appendix VIII to the Report of the U. S. Commissioner 
of Fisheries for 1913 

1 



WATER-POWER DEVELOPMENT IN RELATION TO FISHES AND 
MUSSELS OF THE MISSISSIPPI/ 



INTRODUCTION. 

Begun in January, 1911, and practically completed in June, 1913, 
the dam on the Mississippi between Keokuk, Iowa, and Hamilton, 
111., is not only an eminent feat of engineering and of efficient and 
expeditious construction, but it marks an epoch in man's utilization 
of the greatest North American river. Two hundred thousand 
horsepower are made available for commercial uses, 65 miles of 
water deep enough for unimpeded navigation is provided above the 
dam, and a single lock of the high lift of 40 feet replaces a navigation 
canal and chain of three locks formerly necessary for the passage of 
the Des Moines rapids of the Mississippi, now deeply submerged 
beneath the waters of Lake Cooper. Substantial public benefits 
are combined with the execution of such an enterprise. 

This unique water-power development will have a great signifi- 
cance for the fisheries of the upper Mississippi, not only in the possi- 
ble checking of the upstream movement of migratory fishes, but in 
the large area of lake waters it provides through the submerging of 
former dry land and the backing up of small tributary creeks. It 
is important to point out the significant advantage to fish and mussel 
life of the great additions to the feeding and breeding grounds covered 
by comparatively still water; it is also necessary to call attention to 
the probable deleterious effect of the dam as an obstruction to the 
free movement of fishes from the lower river to the upper, and vice 
versa. How advantage and disadvantage, as regards fish life, are 
to balance against each other in the future is not to be foretold. 
Time and observation alone will show, but it is the purpose of this 
report to present and to analyze the conditions offered by the dam, 
and to point out the opportunities and the importance of subsequent 
observations, as well as to offer certain suggestions for the minimizing 
of harm and the increase of benefit. 

It is hoped, too, that the report may serve the broader purpose of 
pointing out the complexity of the problems involved in the effect 
of water-power development upon fisheries and of bringing out, even 
if inadequately, the opportunities and the fundamental necessity of 

a The Illustrations in thi paper are published by courtesy of the photographer, Mr. Anschutz. 

5 



6 WATER-POWER DEVELOPMENT IN THE MISSISSIPPI. 

a study, not only of fish ways, but also of the migratory habits of 
fishes. There is no view that power development should be sacri- 
ficed to fisheries, but we are shortsighted, indeed, if we do not give 
thoughtful consideration to minimizing any possible sacrifice to 
fisheries that such developments may entail and to enhancing such 
advantages as they may afford. In all the active discussion of 
water-power problems there is almost a painful absence of reference 
to the fisheries aspects, notwithstanding that the food produced by 
the American fresh-water fisheries amounts to upward of 330,000,000 
pounds, with a value to the fishermen alone of more than $12,000,000 
and a value to the consumers far exceeding this amount. 

NEW CONDITIONS AND PROBABLE EFFECT UPON MOVEMENTS OF 

FISHES. 

The writer approaches this inquiry with the conviction that the 
measure of importance of the fisheries of the Mississippi is not found 
in the existing state of the fishery.** The possibilities of the fisheries 
of the Mississippi and other great rivers will be realized only in the 
future, near or remote, when, under the pressure of economic con- 
ditions, and with the illumination of a more adequate knowledge of 
the needs of fish life, fish conservation will be more of an actuality 
than at present. We will then not only comprehend the essential 
importance of conditions favorable to the development of fish food 
and to the natural propagation of fishes, but we will know how to 
supply the necessary conditions. The further belief may be ex- 
pressed that the future will show that Lake Cooper, as the large body 
of repressed water above the Keokuk dam is now known, will prove 
to be an important factor in supplying such conditions and possibly 
may rival Lake Pepin of the North by offering so large an acreage, 
or mileage, of comparatively still water provided with shoals and 
bays sure to be replete with vegetation, and practically free from the 
deleterious conditions incident to the excessive rise and fall charac- 
teristic of ordinary river conditions. 

It is one of the tragedies of fish life, catastrophic in degree at times, 
that the spawning grounds may be found during spring floods far 
from the main course of the river, where an untimely recession will 
leave a generation of young fish isolated in some overflow pond, and 
marked for destruction unless reclaimed by the agency of Govern- 
ment or State. Such fish destruction is evident, and of common 
knowledge, but that which occurs when the flood stage comes late 
and after the fish have found nests in the originally shallow waters 
of the river banks at low stage, can only be guessed at. Accordingly, 
the significance of the interpolation in the course of a great river, 

a The fisheries of the Mississippi River and its tributaries yielded in 1908, as shown by the census report, 
food products of a value well upward of $2,000,000. 



WATER-POWER DEVELOPMENT IN THE MISSISSIPPI. 7 

whether by natural or artificial means, of an immense pool, where 
practically fixed and dependable conditions can be found, is not to be 
lightly esteemed. 

It becomes of greater importance that the possible disadvantages 
incident to such an interpolation should be eliminated as far as 
possible. Lake Pepin of the upper Mississippi, a virtual lake of 
natural origin, is a great natural fish reserve into and out of which 
fish may proceed at will at either end. Lake Cooper of the middle 
region of the Mississippi is an artificial lake into and out of which 
fish may pass unchecked in only one direction. 

Any student of fisheries will at first glance make a further com- 
parison of these two expansions of the Mississippi. The body of Lake 
Pepin has a comparatively straight shore fine and in some places is 
bounded by steep bluffs; there is a relative absence of slues and shal- 
lows favorable for aquatic vegetation. Above and below Lake Pepin, 
however, there are many slues and bayous which offer favorable con- 
ditions for the breeding of fishes, and undoubtedly the fish life of the 
lake is continually replenished from these sources. Lake Cooper, on 
the other hand, has few bluff shores, and throughout its course, except 
very near Keokuk, there are many favorable bayous, creeks, and 
expansions over former agricultural or swampy flats. As regards the 
proportion of deeper waters preferred by some species of fish, the two 
lakes might compare more closely, except that the deep water in Lake 
Cooper is at one end and is less extensive. 

The relation of such developments to mussel life may be briefly 
explained. The very young fresh-water mussels, with rare exception, 
when first liberated from the incubation pouches of the parent, 
must become parasitic upon fishes in order to pass through the next 
stage of their existence. To this end, if the chance offers after 
liberation, the young mussels, or glochidia, as they are called in this 
stage, attach themselves to the gills, fins, or scales of a fish. The 
mussels of economic importance attach themselves almost exclu- 
sively to the gills. In attaching or biting on the fish a very slight 
wound seems to be caused, which begins at once to heal over; but 
in the process of mending, the glochidium is overgrown and thus 
inclosed within the tissues of the fish. The mussel is now actually an 
internal parasite, in which condition it remains for a period of two 
weeks, more or less. It is thus conveyed wherever the fish goes, 
until, when the proper stage of development is reached, it frees 
itself from the host and falls to the bottom; if through a favorable 
fortune it finds suitable lodgment, it continues its growth to form an 
adult mussel. Owing to this fact of active transportation by the 
fish, a mussel born of parents in one part of the river may conclude 
its development in another region, even at points far upstream 
48724°— 14 2 



8 WATER-POWER DEVELOPMENT IN THE MISSISSIPPI. 

from the parent bed or perhaps in some tributary stream that the 
fish host may have entered. 

Investigations carried on by the Bureau during recent years have 
shown that mussels do not necessarily attach to fish indiscriminately, 
but that a given species of mussel may make use of only certain species 
of fish, as the pimple-back mussel (Q. pustulosa) seems to be generally 
restricted in parasitism to certain species of catfishes, and, a more 
striking instance, the niggerhead mussel (Q. ebena) restricts itself 
so far as is known to the river herring, or blue herring, Pomolobus 
c7irysocMoris. a Conditions, therefore, which affect the movements of 
the river herring or the catfish may vitally affect the welfare of these 
important mussels. 

It is not here simply a question of whether mussels will be trans- 
ported from below the dam to the waters above, but, if the river herring 
is a truly migratory fish, going down the river in the fall and ascending 
again in the spring, and, if its course is so checked by the inter- 
position of a dam that comparatively few find the way into the 
upper river, two results will follow: The fish will become a rare species 
in the upper river, and the future generations of niggerhead mussels 
will so generally fail of finding attachment to the only suitable fish, 
that successive broods will perish, until, with the ultimate death or 
capture of the old mussels, the species will become extinct in that 
portion of the river lying above Keokuk; that is to say, in practically 
the entire Mississippi, for the mussel resources of the Mississippi 
proper (tributaries excluded) are exceedingly limited south of Keokuk. 

On the other hand, it is not to be lost sight of that the flood region 
of the repressed water will make available new bottoms for clam 
beds. The future condition is not to be predicted. None of the 
existing bottom of the new lake is definitive. Bottoms now covered 
with former land vegetation will acquire a new character in time 
as they are covered with silt or stream-washed sand. The old 
channel itself, no longer washed as before by active stream action, 
will undergo changes. The Des Moines Rapids was formerly the 
home of abundant niggerhead shells of particularly good quality, 
which could readily be taken from among the rocks. Deeply sub- 
merged as t]p.ese beds now are, it will be scarcely possible to obtain 
the mussels. The gradual accumulation of silt over and among 
these rocks will probably make conditions unfavorable for this species, 
although other beds of different species may be expected to be formed 

« In some publications the name "skipjack" is applied to this species. Except as derived indirectly 
from books, that common name does not seem to be applied to this species by local fishermen. The name 
"skipjack," in fact, seems generally to be appropriately applied to the gizzard shad, while the Pomolobus 
is generally and very appropriately designated as the "river herring," local fishermen having correctly 
recognized its close relationship to the true herrings. It has been learned, however, that the Ohio shad 
(Alosa dhiemis) is not regularly distinguished by fishermen fromthe river herring. To avoid further 
confusion the use of the term "skipjack" as applied to Pomolobus should be discouraged. 



WATER-POWER DEVELOPMENT IN THE MISSISSIPPI. 9 

in other parts. A river-lake a fauna of mussels may replace a strictly 
river fauna. Should Lake Cooper eventually rival Lake Pepin — a 
condition scarcely to be hoped for — it will be one of the most impor- 
tant mussel regions of the country, supporting a mussel fishery 
exceeding anything known in this territory before. 

In concluding this introduction, certain salient points which have 
been brought out or implied merit a particular emphasis. 

(1) While the value of the dam will never be measured by its 
relation to the fishery, the effects, both direct and indirect, will be 
of exceptional interest and importance. There will be advantage 
not unmixed with disadvantage. 

(2) There is a possibility worthy of serious inquiry that some 
provisions may be made to lessen the incidental injury to fish fife. 

(3) The dam will afford a unique opportunity for the study of the 
movement of fishes in the river, if systematic and continuous observa- 
tions be undertaken in the early spring and continued through the 
summer. 

(4) The new-formed lake offers an equally unique opportunity for 
the study of the development of the proper biological conditions for 
fish life. It would be not only a fascinating study, but one of most 
vital significance, to trace the development of this lake from a con- 
dition of infancy to one of maturity, were there available the means 
necessary for such an investigation. 

(5) The opportunity afforded by this new body of water brings the 
responsibility of taking definite measures for stocking it with suitable 
fish and mussels; and scarcely less important is the introduction of 
suitable aquatic vegetation which otherwise, as our experience at 
Fairport indicates 6 will be slow to find a desirable development. 

a By "river-lake," I mean such a body of relatively still water as would ordinarily be called a lake 
which is yet intimately connected with a river, either as interpolated in the course of the river, or as an 
arm of a river. The conditions in a body of this kind may be characteristic. With the opportunity for 
the internal circulation, plankton conditions and community life, corresponding in some degree to typical 
lakes, there are combined in a measure the features of circulation and regular renewal of water correspond- 
ing more nearly to usual river conditions. Illustrations are Cross and Pokegama Lakes in Minnesota 
Lake Pepin and Lake St. Croix, and in a smaller way, Rice Lake at La Crosse, Wis., which is between 
the Mississippi and Black Rivers and connected with both. Lake and river faunas are generally quite 
distinct in character. In fact, it is rare for a lake to yield commercial mussels. In the instances just men- 
tioned we find, however, characteristic river mussels, and, what is more striking, we find that a species 
such as the so-called fat mucket (L. Ivtcola), which is generally abundant and worthless in true lakes, is in 
these river-lakes abundant and valuable— that is, it has a shell of such thickness and form as to be excep- 
tionally useful for buttons. The adaptations of this species is an interesting chapter in itself. No other 
species of mussel is so generally worthless and, at the same time, so exceptionally valuable and abundant 
in particular regions. Are its good qualities attributable to the unusual combination of river and lake 
conditions, or are they characteristic of a geographic region? Will the same species attain importance in 
Lake Cooper? When the latter question is answered, as it will be in course of a few years, the answer to 
the former question will be supplied at the same time. 

b The Bureau through the Fairport station has already made some plants of fish and mussels, and since 
this paper has gone to press has undertaken a preliminary study of the plankton of portions of the lake 
with a view of tracing in this and subsequent years the development of the content of fish food. Further 
observations are inserted in another portion of the paper. 



10 WATER-POWER DEVELOPMENT IN THE MISSISSIPPI. 

(6) The lessons which can be learned at Keokuk, if the opportunity 
can be availed of, will be of far-reaching importance as supplying a 
basis of information for guidance in future developments upon the 
Mississippi or upon other rivers. 

PRELIMINARY OBSERVATIONS. 

In June, 1913, it was brouglit to the writer's attention that the 
Keokuk dam was being filled witn water and, therefore, that a portion 
of the river bottom below the dam might be exposed for observation. 
The idea immediately occurred that the practical stoppage of water 
during the process of filling might cause the congregation of large 
numbers of migratory fish below the dam, including the river herring 
which had for some time been sought without success both at New 
Boston and at Fairport. Mr. Thaddeus Surber, being then engaged 
upon the investigation of the river herring, was therefore advised to 
proceed to Keokuk in the hope of finding the desired fish and of 
securing needed mussels if beds were indeed exposed. The expecta- 
tion in regard to the fish was fully realized. The fish which had been 
sought fruitlessly at Fairport and New Boston were found abundantly 
immediately below the dam. 

After an inquiry from the Mississippi River Power Co. regarding 
the movement of fish, a second visit by Mr. Surber was made July 
10 and 11. He reported almost incredible numbers of fish lying 
just below the dam, large numbers of which were being caught by 
local residents using hook and line, dipnets, hay forks, etc. During 
this visit the gates were closed on the Illinois end of the dam, thus 
leaving the new bed of the river fully exposed where previously there 
had been water 3 to 6 feet deep. Vast numbers of fish were left 
stranded and struggling about in the little pools among the large 
stones, and people from both sides of the river were reaping a harvest, 
some with gunny sacks filled, others with the larger fish slung on 
poles, while others still were contented with long strings of fiddlers, 
sheepshead, etc. He estimated that 1£ tons of fish were removed 
in the course of a couple of hours. 

Below the dam on the 10th and 11th the following fish were 
observed, given in order of their abundance: Buffalo, carp, paddle- 
fish, sturgeon, sheepshead, fiddlers, redhorse, bluefish (Cycleptus) , 
toothed herring, and hickory shad. Very few bass and crappie were 
taken, though they were reported to be unusually abundant; no 
Pomolohus at all were secured, and, according to local informants, 
none had been taken for several days previously. 

I visited the dam September 22 and 23 and again October 11-15, 
1913. The administration of the company courteously granted 
passes for examination of the dam and its works and extended all 



WATER-POWER DEVELOPMENT IN THE MISSISSIPPI. 11 

information requested. The lock was also operated for purpose of 
demonstration. 

DESCRIPTION OF THE KEOKUK DAM. 

The figures and essential data regarding the construction plan are 
largely gleaned from a lucid description of the dam comprised in a 
booklet entitled "Electric Power from the Mississippi River" and 
issued by the Mississippi River Power Co., at Keokuk in 1912 
and 1913. 

The plant consists of the following principal elements (see pi. n) : 
A dam proper, 53 feet high over all and four-fifths of a mile 
long, extending across the Mississippi from the Illinois shore at Ham- 
ilton and connecting at its western end with the power house, which 
is built in the river several hundred feet from the Iowa shore; the 
power house has its length almost parallel with the river shore, 
extending in a downstream direction from the terminus of the dam 
proper, and is practically one- third of a mile in length, over 132 feet 
wide, and with the great height of 177 feet 6 inches or from 25 feet 
below the surface of the limestone river bottom to nearly 110 feet 
above the surface of the lake at high water; the lower end of the 
power house (one-third of a mile below the dam) is joined to the Iowa 
shore by a series of constructions, including a section of dam about 
100 feet long, which provides a narrow chute and houses the machin- 
ery for operation of the lock and dry dock, the lock 110 feet wide and 
400 feet long, inside dimensions (618 feet over all), and the dry dock, 
150 by 463 feet. 

It thus appears that a bay or harbor of considerable size is formed 
between the power house and the Iowa shore, limited on the lower 
side by the lock and dry dock. This is called the fore bay and is 
protected on its upper side by a curved ice fender composed of con- 
crete arches in a series 2,325 feet long and 300 feet of floating boom 
which may be opened back during the navigation season. It extends 
from the upper eastern or offshore corner of the power house (that 
is, from the western terminus of the dam) to the Iowa shore, the 
direction being somewhat curved, and the total length about half 
a mile. 

The parts which are of immediate interest to us are the dam, the 
power house, and the lock. 

THE DAM STRUCTURE. 

The dam proper is merely for the repression of water and the 
provision of spillways. It is 4,278 feet long, or, with its abutments, 
practically 1 mile. (PL II.) 

"I desire to acknowledge the courtesy of Maj. M. Meigs, United States engineer, who extended me the 
privilege of examination of the lock and facilitated my investigation in other ways. 



12 WATER-POWER DEVELOPMENT IN THE MISSISSIPPI. 

The dam structure is composed of 119 spans, each consisting of 
two piers supporting an arch, which upholds a causeway. Between 
the piers is placed in each span a section of spillway, the part over 
which the water flows. This bridge-like structure, with the water 
flowing over the spillway sections, extends from the Illinois bluff, 
to which it is tied by an abutment, across the river to the upper 
outer corner of the power house on the Iowa side, to which it is 
tied by another abutment. 

The piers are 6 feet thick, and the distance between piers — that is, 
the width of each of the 119 spillway sections — is 30 feet. The 
height of spillways is 32 feet. The upstream face of each spillway 
section is vertical, the downstream face having a curve designed to 
conform to the under surface of a body of water of this size and 
depth running over a vertical obstruction to the current; the spill- 
way face is made to fit the under surface of the water to avoid fric- 
tion as much as possible; the curve of the downstream face delivers 
the water in a horizontal direction down the river. (PI. n.) 

The stream over the spillway has a depth between 7 and 1 1 feet. 
We thus have at each spillway in use an unretarded waterfall of 
considerable volume with an abrupt drop of 32 to 40 feet, deflected 
only at the bottom, where it shoots out among the rocks with im- 
mense force in the form of a raging, foaming torrent, dashing against 
the rocks with indescribable commotion. For the protection of the 
base of the dam from the erosion due to back currents, a broad, 
low concrete apron is now being laid to flank the dam on its lower 
side. It would be impossible for a fish to ascend such a fall from 
below, or even, in all probability, to pass downward through it and 
escape alive. This is inevitable to the existence of such a dam, so 
that the opportunity for fish passage must be sought elsewhere. 

Between the top of each spillway and the lower side of the over- 
hanging causeway is an arched opening about 19 by 30 feet which 
will permit the passage of ice and drift with the water. These open- 
ings are partially closed by steel gates, 11 by 32 feet, which work in 
deep slots in the concrete and serve to control the head within cer- 
tain limits, as well as to regulate the flow to conform with the mini- 
mum requirements for navigation as determined by the Govern- 
ment. 

The dam proper is not at right angles to the course of the river 
below but has a slight downstream direction from east to west, so 
that the upstream end of the dam structure, as of the entire plant, 
is on the Illinois side. In ordinary times only a few of the spillways 
are in use simultaneously, so that the main stream of the river so 
far as it is determined by the flowage over the spillways — the waste 
water, so to speak — may be changed at any moment from one side 
of the river's course to the other through a distance of nearly a 



WATER-POWEK DEVELOPMENT IN THE MISSISSIPPI. 13 

mile. (PL 11.) In practice it is found necessary to be continually 
changing the gates in order that all may be in perfect order and no 
risk be run of any gate sticking or failing of operation at a critical 
time. The gates are raised or lowered by traveling cranes and 
require about 13 minutes to lower. 

Accordingly, as regards those fishes which are seeking an upstream 
destination, so far as their course may be determined by the spillway 
current, they will be directed toward the foot of the dam or to the 
outskirts of a small sea of raging waters (at one side or the other, or 
midway of the river), where in any case they are confronted by an 
impassable barrier. If the stream is suddenly changed by the closure 
of gates at one place and opening of others in another part, the fish 
may be left in enormous quantities in the suddenly isolated pools 
among the rocks, where they are at the mercy of those who would 
capture them. Just this condition has occurred on some occasions 
when fish coidd be taken with clubs and hay forks or with any con- 
venient tool. This condition is more or less inevitable, but its recog- 
nition may serve to suggest the necessity for care that the condition 
be not caused unnecessarily. In any case stringent measures should 
prohibit the slaughter of these fish and provide for their rescue and 
restoration to the river. It is probably within the province of the 
Government, in conjunction with the power company, to prevent the 
wanton destruction of the fish left suddenly helpless under an emer- 
gency condition. 

THE POWER HOUSE. 

The power house is of great importance, not only as the actual seat 
of the machinery which converts water head into power in utilizable 
form, but as the place through which there will always be passing a 
considerable quantity of water. (PI. in.) The spillways of the 
dam, it will be understood, serve only to supplement the flow of 
water through the power house, taking care of the elements of fluc- 
tuation in the volume of the river and of variability in the use of 
water for power. 

The power house is not alongshore, but arises out of the body of 
the lake, as it were, forming the eastern boundary of the fore bay, 
for about one-third of a mile (pi. i.) Its exact length as designed 
is 1,718 feet, but only one section equal to one-half of this length 
is now completed. The foundation walls of the entire building are, 
of course, in place as an essential part of the dam as a whole. The 
outside wall of the building toward the Iowa shore is not built 
solid to the bottom, but is supported on a series of arches, so that 
the water from the fore bay has free access to an inner or head bay 
within the building and extending its entire length. The outer wall 
of the building, facing the Illinois shore, rises from the downstream 



14 WATER-POWER DEVELOPMENT IN" THE MISSISSIPPI. 

bed of the river and is flanked by the tail-race or tail-bay, an impor- 
tant feature for our consideration. Between the head-bay and the 
tail-race intervene the turbines or power units, of which there are now 

15 installed and 15 more in contemplation. These are arranged in a 
single linear series from the upper to the lower ends of the house. 

The water from the head bay is admitted to each turbine through 
four gates, each 22 feet high by 7 feet 6 inches wide, the opening 
being protected by coarse screens or iron gratings, which exclude the 
passage of large drift, but are not fine enough to prevent the passage 
of any but the largest fish; the openings between bars of the grat- 
ings are 6 by 23 inches. The four intake passageways are of a 
special design and converge into a single large scroll chamber 39 feet 
in diameter around the turbine. Other gates or guide vanes at this 
place control the passage of water into the turbine chamber, whence, 
after setting the turbines in motion, the water passes down through 
the enlarging draft chamber out into the tail-bay below. The draft 
chamber is circular at its upper end just below the turbine, where it 
is 15 feet in diameter, or about 2 feet greater than the diameter of the 
water passage through the turbines. At once, however, it begins 
to enlarge in diameter and take a curved form by which it changes 
direction from the vertical to the horizontal and changes from a cir- 
cular to an oblong shape in cross section. The outer openings of the 
draft tube below are 22 feet 8 inches in vertical diameter and 40 feet 
2 inches in horizontal diameter. The bottom of these openings and 
the bottom of the tail-race is about 25 feet below the bottom of the 
Mississippi. 

Between the head-bay and the tail-race there is normally a head of 
32 feet. It is calculated that the velocity of the water at the top of 
the draft tube, immediately under the turbine, will normally be 14 
feet per second, or 9 miles per hour, while at the point of discharge 
into the tail-race it will be 4 feet per second, or less than 3 miles per 
hour. The water in the tail-race itself may have a greater velocity. 

It has been complained that many fish are destroyed by the tur- 
bines. It is possible that descent through the turbines would be 
fatal, but it is scarcely conceivable that fish in course of ascent 
would reach the turbines. It is to be remembered that the water 
passes the turbines in course of a vertical descent of 32 to 40 feet 
with greatest velocity where the turbines intervene. It is hardly 
possible that fish would successfully breast a vertical current of such 
force. It is not generally the swiftest fish that seek the darkest 
passageways. The blades or buckets of the turbines, of course, 
though revolving at high speed, are not slashing through the water 
as the uninitiated might suppose, but are driven before the water. 
Assuming, therefore, that a fish could make the tortuous passage 
from tail-race to head-bay against the velocity of the water, the tur- 



WATER-POWER DEVELOPMENT IN THE MISSISSIPPI. 15 

bine buckets would probably interfere less with its course than the 
solid walls that confine the water. 

There are not infrequent reports of the finding of specimens of the 
spoonbill-cat or paddle-fish below the dam, with the spoonbill cut 
or broken clean off. Such injuries are attributed to the blades of 
the turbines, but the reports have not been as yet of such frequency 
as to indicate any serious degree of damage. 

The bottoms of the lower openings of the draft tubes are 25 feet 
below the natural bottom of the Mississippi. (See p. 14.) The tail- 
race is excavated to a corresponding depth from the upper end of 
the power house down to the region of the lock below. This is, for 
our purpose, one of the most significant features of the dam. The 
tail-race constitutes a narrow but deep channel, through which the 
water used in the power house is conveyed downstream to join the 
natural main channel of the river on the Iowa side near the bridge. 
The remainder of the river bed conveys, besides an overflow from this 
tail-race, only the spilled water from the dam, which may at various 
times be greater or less than the flow in the tail-race, according to the 
stage of the river above. It may be imagined that at the ultimate 
development of the plant the amount of water used regularly in the 
power house will be approximately equal to the minimum low-water 
volume of the river, since the storage capacity of the lake is not 
considerable as compared with the size of the plant. 

Not all of the water from the draft tubes will follow the direct 
course, for the channel is not strictly confined, and a considerable 
surface current will always overflow from the tail-race toward the 
body of the river. At the time of this writing (October, 1913) the 
tail-race is to a considerable extent confined by the old cofferdam; 
but it is probable that this will be blasted out, permitting more 
extended lateral overflow. There will always be a strong flow of 
water in the tail-race corresponding at least to the volume of water 
required to supply the minimum demands of power. There will 
probably be little fluctuation of current from day to day at corre- 
sponding hours except with seasonal changes of fighting demands, 
but there will be a regular ebb and flow (considering the tail-race only) 
in the course of each 24 hours, since the use of electrical power is 
usually least during the early hours of the morning. This variation 
is very carefully watched by the company, so that it may be com- 
pensated by opening or closing gates over the spillways of the dam 
to minimize the effect on navigation in the river below. 

The tail-race is the one perpetual passageway for water below the 
dam, and it is of interest to inquire in a later paragraph if the fish 
which may be attracted against this current may not be deflected 
by some simple means toward the only avenue of escape into the 

a Several cases have come under the writer's observation. 



16 WATER-POWER DEVELOPMENT IN THE MISSISSIPPI. 

waters above. The tail-race will always be comparatively free from 
drift or ice, which must be screened out above for protection of the 
turbines. It will not be strictly free of drift below the power house 
on account of there being in the lower end of the power house a 
small spillway, or chute, through which drift that has entered the 
head-bay may be shunted to the tail-race below. Close to this chute 
but just without the west power-house wall, is another small spill- 
way for shunting the drift which may collect in the region of the 
lock. 

THE LOCK. 

The lock was an essential requirement of the Government in 
order to provide for the necessities of navigation. It is of pax'ticular 
interest also since it is the only passageway by which it is supposed 
fish may pass from the lower river to the upper. The lock, built by 
the proprietors of the dam and deeded to the Government, is located 
below the power house and inshore from it, the upper eastern corner 
of the lock being connected with the lower western corner of the 
power house by a short section of dam provided with narrow spill- 
ways, as before mentioned. (PI. i.) The lock is 110 feet wide and 
400 feet long inside and has a maximum lift of 40 feet. The time 
required for locking a boat through is about 15 minutes. For such 
a great lift in so large a lock to be accomplished in so short a time 
requires a most efficient and special arrangement for filling and 
emptying the lock. 

The bottom of the lock (which is 8 feet below the water level at 
the lowest stage of the river) is a gridiron of culverts, the mains 
being under the bottom of the walls running lengthwise of the lock, 
and the crossbars of the gridiron being culverts crossing the lock 
floor at intervals. The largest of these culverts are 13 feet in diameter 
and the smallest are 6 feet in diameter. The culverts are cast of 
concrete around steel lining. The angles in them are so sharp 
and the water pressure and velocity will be so great that the friction 
of the water against the concrete would wear the latter if it were 
not protected with steel. The outlet ends of the culverts discharge 
on the side of the lock at right angles to the course of the river. 

By adjustment of a series of valves the water in the lock is permitted 
to run out into the river through the culverts. After the boat has 
entered and the gates are closed, the culvert valves of the filling 
system will be opened, the water from the higher level of the fore 
bay will rush through the culverts entering the lock chambers through 
fifty-seven 3-foot culvert openings until the level within the lock is 
the same as that of the fore bay, the boat being lifted 40 feet 
vertically within a few minutes. (PI. vi.) As soon as the upper 
gate is submerged the boat may pass out and continue its course 
through the deep water of the bay and lake. In leaving the lock 



WATER-POWER DEVELOPMENT IN THE MISSISSIPPI. 17 

the boat passes over the front wall of the lock which is covered by 8 
to 14 feet of water, according to the stage of the lake. 

It should be remarked that the lower gates, which are of heavy 
steel truss construction, swing open, while the upper gate is of a new 
submerging type. This gate is a heavy steel truss containing air 
chambers below and works up and down in vertical slots of steel. 
There is also an emergency gate a short distance in front of the regu- 
lar upper gate which may be used when necessary to repair the latter. 

It will be inferred from the above description that the fish would 
not be likely to enter the lock from below during the process of 
emptying, since to do so would be to pass through the deeply sub- 
merged sharp-angle, culverts or tunnels out of which the water is 
discharging apparently at enormous velocity. Correspondingly it 
is not to be expected that they would gain the upper lake from the 
lock during the process of filling, since to do so entails passing down 
through the same tunnels against the rush of water under a 40-foot 
head. It is possible that a few might make their exit in this way 
after the lock is nearly filled. 

It is also clear from the description of the working of the lock that 
the gate above is not submerged except when the lock is full, nor are 
the gates below opened except when the lock is empty. In other 
words, there is no ingress or egress through the gates for fish that are 
working upstream except when the water in the lock is stationary, 
which is to say, when ascending fish are least tempted to move in 
that direction. 

Another feature of the lock construction is significant. The upper 
opening of the lock does not extend down to the bottom, but is 
largely closed from below by a solid concrete wall over 30 feet high. 
(PI. vi). A fish entering the empty lock from below finds 8 feet 
of water at the lowest stage of the river; leaving the full lock above 
it finds 8 to 14 feet of water between the top of the submerged gate 
and the lake surface according to the stage of the lake. To find its 
way out, therefore, it must make a vertical rise of 25 to 35 feet, 
without the presence of any definite current to direct its movements, 
or else, as before mentioned, it may seek its way out through the 
deep tunnels beneath. How will this head wall affect the movements 
of bottom-loving fish ? 

Parenthetically, it may be said that the effect of the unwonted 
variation in pressure within the lock may have a real (but quite 
unknown) influence on the movement of fishes. The depth of water 
in the lock varies from 8 to 48 feet. The possible demoralization of 
the fish by the turbulence of waters suddenly boiling up from below 
under a 30 to 40 foot head is perhaps uncertain, though we may 
infer that its effect would not be the happiest. 



18 WATER-POWER DEVELOPMENT IN THE MISSISSIPPI. 

As a matter of observation, fish are found in the lock. When the 
lock is emptied a few fish are often seen stranded on the broad top of 
the wall at the upper end of the lock. More often, perhaps invariably, 
some are caught between the rails on the top of the submerged gate 
when this is raised. The space between these rails is about 8 by 
110 feet or 880 square feet. Only a few fish were thus taken under 
my observation, but I was informed that as many as 50 to 100 had 
been caught in this way at one time. We do not know whether these 
fish were going into or coming out of the lock. It is possible that the 
lock acts as a sort of fish trap into which fish of the immediate vicin- 
ity stray, and by means of which some of these fish are transferred 
infrequently from pool to river, or vice versa, without reference to 
migratory movement. The lock chamber is a little over an acre in 
extent (44,000 square feet) and such an area in nature will accom- 
modate a large number of fish without indicating any special assem- 
blage of fish seeking a passage in a definite direction. The actual 
fact, and the significance of the facts, may be determined only by 
systematic observations judiciously interpreted. 

THE QUESTION OF A PRACTICAL AND EFFECTIVE FISHWAY. 

At the outset it may be stated that an ideal fishway is afforded 
only by the free channel of the river itself. We can not have water 
powers in the course of the stream, without some sacrifice of the free 
movements of fishes. Artificial fishways may, however, be practi- 
cally effective, and locks are sometimes accepted as proper fishways, 
especially where occurring in the course of canals or narrow streams. 
It does not follow that a lock will be effective in all situations. Some 
features of the present case will first be recapitulated. 

(1) The position of the lock is near the Iowa shore, from which it is 
separated only by the dry dock and the Government reservation on 
filled ground built out from the shore. (PL I.) 

(2) The width of the lock opening is 110 feet, as compared with 
the approximately three-fourths of a mile breadth of the river. Its 
opening is perhaps one-thirtieth of the width of the river. 

(3) The location of the lock is out of the principal currents, though 
not far removed from the important tail-race. It is not certain, 
therefore, that even a proportion of the fish equal to the ratio of the 
width of the lock to the width of the river would find entrance to the 
lake through this chamber. That a considerable number of fish 
should be found in the lock is not inconsistent with this statement. 

(4) The filling and emptying of the lock is accomplished by meth- 
ods which do not encourage the entrance or exit of migratory fishes 
during these processes. Fish may freely enter from below when the 
lower gates are open and, by rising toward the surface, may leave for 
the lake when the gate at the head is opened; but at these times the 



WATER-POWER DEVELOPMENT IN THE MISSISSIPPI. 19 

water in the lock chamber is practically stationary. It has been sug- 
gested that this defect might be remedied by providing in some way 
that a slow but practically continuous flow of water might prevail 
through the lock. 

(5) There are factors of pressure and of serious disturbance or 
turbulence of the water which may have significant effect upon the 
moving tendencies of fish in the locks. 

(6) The lock is operated on an average about nine times a day, 
during the season of navigation, and requires from 15 to 30 minutes 
for the passage of one or more boats. 

(7) The movements of fishes can not be subjected to rules, nor 
even accurately defined, except after such patient and systematic 
observations as have not yet been made. 

Any fishway to be effective, must receive the fish at some point of 
convergence and give them practically uninterrupted opportunity 
for ascent. The fishway should be in operation at least as early as 
the ice goes out in spring, and preferably sooner, and it should be so 
attended and cared for as to be always in unobstructed condition. 
The lock can not be said to meet these conditions. 

The engineering difficulties of providing an effective fishway over 
a dam 40 feet high and a mile wide are not to be underestimated, and 
must be given careful consideration. Were it an impossibility to 
have a fishway under these circumstances, we should simply have to 
fall back upon the law of compensation and accept a great loss in 
exchange for a greater benefit. The stakes to be lost are, however, 
perhaps greater than may at first be supposed. The reduction of 
important fisheries in the entire upper Mississippi and the possible 
extinction of one of the most valuable mussels of the same portion of 
the stream are not to be lightly considered. 

It is not impossible to suppose that practically all fish that 
approach the lower end of the tail-race could be made to converge 
toward the position of the lock or its juncture with the power house. 
It is possible that an open weir of coarse-meshed wire netting 
stretched out as a wing from the foot of the lock entirely across the 
stream below the tail-race would accomplish this purpose. The 
feasibility of this is suggested by the fact that the tail-race is so 
largely free from dangerous drift materials. A decided downstream 
angle to the wing net would not only increase its efficiency but would 
facilitate the passage around the end of the weir of the drift not 
screened out above, even if some attention were required to insure 
such clearance. 

The desirability of a fishway at any point depends upon determina- 
tion b}^ experiment as to whether a large proportion of the fish could be 

a Records from the lockmaster's book for a period of 46 days show 224 lockings "down" and 191 lockings 
"up," or a total of 415 operations. 



20 WATER-POWER DEVELOPMENT IN THE MISSISSIPPI. 

concentrated at this place. Some simple experimentation is worth 
while, if only for guidance in case of future constructions. Were there 
installed a floating boom directed from the lower offshore angle of the 
lock structure downward and outward across the main flow from the 
power house, it would be practicable for experimental purposes to 
supplement this by suspending a weir of coarse-meshed wire netting 
below the boom. The object would be to determine whether fish in 
large numbers could be deflected in the direction of the lock. The 
possibility of a fishway near the Illinois end of the dam, which, as has 
been brought out, is the point farthest upstream, is also worthy of 
consideration ; although the difficulties are here greater, on account of 
the exposure to floating ice and other drift, and because of the changes 
of flow from one part of the dam to another. It is possible that, after 
the period of construction is entirely passed, it will not be necessary 
to make entire changes of flow during the season of active migration of 
the fishes. It may be borne in mind that, on account of the tremen- 
dous disturbance resulting at the foot of the spillways, most fish 
will find their direct approach checked at several hundred feet from 
the base of the dam, although they may, and do, pass around the 
region of disturbance to reach the very foot of the dam. Accordingly 
a fishway having its foot at some distance from the dam might be 
in position to receive the fish at the uppermost point of direct 
approach. 

Reverting again to the tailrace as a region of unceasing current, 
one may look down from the platform along the outside wall of the 
power house upon the upper part of the tailrace, where the big draft 
tubes are discharging columns of water 25 by 40 feet, directed with 
great force against the opposite face of the tail-bay some 75 feet from 
the power house. Meeting this obstruction, the waters are thrown 
into terrific commotion before they can be turned downstream to 
follow the direction of the excavated raceway. In this raging, whirl- 
ing, ebullient current, no fish could find a rest or pursue a definite 
course. But the water is always overflowing now between the piers 
of the abandoned cofferdam flanking the tail-bay, and will, after the 
cofferdam is entirely removed, overflow in a continuous sheet toward 
the center of the river. This is of interest as a tolerably fixed condi- 
tion, as opposed to the variable conditions characteristic of the spill- 
way portion of the dam.° It appears plausible that fish will work up 
along this line of overflow, finding ultimately a terminus at the foot 
of the dam. Tf it be possible to provide a fishway on the dam at a 
point near the upper end of the tail-race, it is probable that the oppor- 
tunity for concentration of fish would be more uniform here than at 
any other point on the dam proper, and likewise that the problem of 
preventing damage from floating ice and drift would be simplified 

a Note the later observations Inserted on page 25. 



WATER-POWER DEVELOPMENT IN THE MISSISSIPPI. 21 

by the proximity of the head of the fishway to the power house and 
the present ice fender. 

The possibility of a dipnet and hoist operated at the angle of power- 
house and dam, or elsewhere, is suggested by the congregation of fish 
in such places. None of the suggestions mentioned in this section is 
offered as a practical solution of the problem; rather as indicating 
some possible lines of preliminary experiment. 

Finally, the question is sometimes asked if fish in migration are 
working along the bottom or near the surface. The answer is that 
there are bottom-loving fishes and surface fishes. The essential fact is 
that a fishway is intended for the use of fish working upstream, or 
those engaged upon the return journey. Consequently it must be 
located at a point that fish naturally approach in fighting a current. 
Needless to say, it should operate continuously, and not intermit- 
tently, unless the fish were prevented in some way from seeking 
another place while waiting for the opening of the way. 

It is much easier to proclaim the desirability of a fishway than to 
say what sort of a fishway and what location for it would be practi- 
cally effective. The problem which is raised is simply this : To deter- 
mine by continued observation under varying conditions at what 
points the fish naturally converge or may, by artificial means, be 
made to converge ; then to inquire what sort of passageway would be 
practicable and effective to permit and encourage ascending fishes to 
rise from the river to the lake. When these questions are given a 
definite answer, intelligent action can follow. If the end is neces- 
sary, and practicable of attainment, it is worth expense; if it is not 
found feasible to converge and give reasonably free passage to migra- 
tory fish, it is useless to waste relatively large sums for the name of 
"fishway." The whole matter at this stage may be expressed as a 
biological problem, definitive answer to which should not and can not 
be given except on the basis of further experience. 

LAKE COOPER. 

It is indeed desirable that ascending fish should have access to the 
great breeding grounds of Lake Cooper. Regarding the lake, it is 
not pertinent in this connection to add much to the references made 
in the introduction concerning its relation to fish and mussel life. 

As a region of repressed, and relatively slack water, Lake Cooper 
extends above Burlington, Iowa, with a length of 65 miles and a 
width of 1 to 3 miles. It will not here be discussed except to remark 
that it has caused the submergence of many islands and low-lying 
shoreland and formed numerous deep coves and bays. Much of the 
submerged farming lands of high value are to be reclaimed by systems 
of levees and drainage. The growth of trees upon many of the flooded 
islands and shores has been removed by the company that there 



22 WATER-POWER DEVELOPMENT IN THE MISSISSIPPI. 

might be no danger to navigation. The maximum lake level is not 
yet attained; there may be a rise of 3 or 4 feet in the course of the 
next few years, to be made gradually in accordance with arrange- 
ments between the company and the property owners affected. The 
greatest depth in ordinary times will be about 40 feet, but the gen- 
eral depth will be much less. 

There will ensue a good deal of decomposition of old land vegeta- 
tion under water, but the effect of waves and surface wind currents, 
in connection with the circulation resulting from the regular flow of 
the river, will do much to reoxygenate the water. In course of time 
a proper growth of vegetation will be found in the bays, and this will 
form a most significant feature in the bionomics of the mature lake. 

Experience at Fairport with new ponds supplied with Mississippi 
River water shows that the development of a proper degree of aquatic 
vegetation is greatly hastened by artificial introduction of suitable 
plants, and we have found it difficult to obtain these in any variety 
from the local overflow ponds and slues of the Mississippi. It 
would be most desirable, therefore, if the Government or State 
authorities should make such introductions in the various coves and 
bayous, so that the maturity of the pond as a fish environment might 
be expedited. Plants of fish and mussels can readily be made. It is 
understood that several hundred young bass were introduced by the 
Iowa State fishery department, and the United States Bureau of 
Fisheries, through the Fairport Biological Station, made a plant in Oc- 
tober, 1913, of 2,343 large-mouth black bass and 425 crappie infected 
with Lake Pepin muckets and local Mississippi River muckets, in 
about equal proportions (1,380,000 glochidia in all). 

OPPORTUNITY AND RESPONSIBILITY FOR INVESTIGATIONS. 

The problem presented by the Keokuk Dam may well serve to 
point out the inadequacy of our preparation to deal with situations 
of the kind — situations which may vitally affect the future food supply 
of our people. It is not alone an insufficiency of knowledge and ex- 
perience which confronts us, but a real negligence. In connection 
with water-power developments everywhere, streams are obstructed 
with the bare and indefinite requirement for installation of fishways, 
which, in a large number of cases, become inoperative soon after they 
are put in. It is not the proprietors of the power developments who 
are at fault, so much as the public at large who expect the owners to 
provide and maintain fishways though robbed of incentive and 
guidance. 

The subject of fishways is one of live importance, and one requiring 
thorough experimentation. It is not the method of laboratory ex- 
periment that is needed, so much as that of field experiment and 

a There are very few sorts of fishways that accomplish the purpose for which they are designed. 



WATER-POWER DEVELOPMENT IN THE MISSISSIPPI. 23 

continued observation of the movements of fishes and their utili- 
zation of fishways. It is unfortunate that more practical experience 
has not been gained by a strict enforcement of the provisions requiring 
fishways and subsequent precise observation of their efficient working. 
In this way would the best of experience be gained. 

Passing this subject, there are rare opportunities presented by the 
situation at Keokuk, to take advantage of which would be of the 
highest value. 

We are deficient in our knowledge of the movements of fishes. 
What fishes migrate, at exactly what season does the migration occur 
with the several species of fish, and what is the extent of the move- 
ment with the several species ? These are questions that we can not 
now answer with a satisfactory degree of definiteness. The existence 
of a practical obstruction in the Mississippi at Keokuk offers an 
unprecedented chance for exact observations, supplemented as they 
may be by the series of observations made by the biological station 
at Fairport, in the upper Mississippi at Lake Pepin, and elsewhere. 
The full realization of this opportunity can not be accomplished by a 
cursory examination, but demands a systematic and long-continued 
investigation undertaken before the movement of ice in the spring. 

Observations made by the staff of the Fairport station during the 
summer and fall of 1913 have revealed the fact that the river herring 
(Pomolobus chrysocTiloris) has been present just below the dam during 
practically the entire period and in large numbers. Nevertheless, 
it would be impossible to say at the present time if this is because the 
fish are blocked in the effort to proceed up the river, or if we have to 
do only with the assemblage of an exceptional number of individuals 
of this species due to peculiarly favorable conditions found in the 
swift waters below the dam. 

The peculiar habits of eels are of particular interest in connection 
with any effective obstruction of the course of a stream. It is known 
of some species of eels, and believed to be true of all, that they do not 
breed in the rivers at all, but only in the depths of the ocean. The 
young eels, after hatching from the egg and passing through an inter- 
esting stage called the leptocephalus, during which they are strictly 
marine, ascend the rivers to grow to maturity, when they in turn will 
pass down the rivers to start a new generation upon the first stage of 
life in the sea. Supposing that few of the new generation of eels 
should succeed in passing above the dam, we would expect a gradual 

« Anadromous fishes are those which ascend rivers to spawn; the only fish of the Mississippi assumed to 
be anadromous is the Ohio shad, Alosa ohiensis. Catadromous fishes are those that go down to the sea to 
spawn; such are the eels of the Mississippi River. Other fishes are merely migratory having seasonal runs, 
from upper to lower portions of the river and return. In this class are generally included practically every 
important food fish, as the basses, wall-eyed pike, suckers, buffaloes, spoon-bill cat, lake sturgeon, shovel 
nose sturgeon, river herring, and all the larger catfishes. Very few fishes, among which would be the bull- 
heads, would be left in the nonmigratory or permanent resident class. However, it must be said that the 
beliefs regarding the movements of fishes require to be submitted to the test of more exact observation. 



24 WATER-POWER DEVELOPMENT IN THE MISSISSIPPI. 

extinction of the eel in the upper river and its tributaries, while we 
would look for a relative abundance of young eels below the dam, 
particularly during the next few years. This is a problem that may 
lend itself to concrete observation. 

A question that raises itself in regard to purely migratory fishes, 
that is, those that move down the river in the fall and up in the spring, 
is, to what extent will the presence of the large body of deep water 
above the dam remove the necessity, or inhibit the tendency, of the 
fishes to proceed farther in their downstream course ? 

The destiny of the fish that are interrupted in their upward journey 
upon reaching Keokuk introduces a new problem. What becomes of 
these fish ? Will they remain there all the summer ? Will they turn 
back and work down the river or find tributary streams ? To answer 
such questions would require close and continuous attention during 
the spring, and, since the fish can not be watched by the eye, a good 
deal of systematic trapping and seining at various points. In this 
connection it may be mentioned that reports were current to the 
effect that the Keokuk dam had turned innumerable fishes up the 
Des Moines River, which discharges into the Mississippi only 3 miles 
below the dam. It was said that more fish were being taken at 
Ottumwa than could be disposed of. Both Ottumwa and Eldon 
were visited by the writer in September, and the most careful inquiries 
made. It was found that the reports had no foundation, other than 
the hope and belief that the dam would deflect the fish into the Des 
Moines River as the first opening below Keokuk. Some local per- 
sons who did not fish offered some supposed confirmation of the 
reports, but every one of a considerable number of persons inter- 
viewed who fished either as a profession or for sport, agreed in stating 
that the fishing had been unusually poor during this season, and this 
condition was attributed to the fact that the river had been too low 
all the season for fish to ascend. There was some testimony that 
there had been an unusual run of very small channel cats and carp of 
6 or 7 inch length — almost too small to use — but it did not appear 
that this had been unprecedented; also there was complaint of an 
increasing number of gars. 

The sudden creation of a large lake intervening in the course of a 
great river with the submergence of islands and shore land, thousands 
of acres in extent, offers an unrivaled opportunity for investigations 
of material value. Upon this subject we are at liberty to some extent 
to draw conclusions a priori, as has been done, but there is none the 
less the privilege and the responsibility for more detailed inquiry and 
exact survey which, if completed, would furnish invaluable data for 
interpretation of the conditions of fish life and the determination of 
the ultimate requirements for the maximum development of fishery 
resources. 



WATER-POWER DEVELOPMENT IN THE MISSISSIPPI. 25 

The problems here outlined are too extensive in scope to be solved 
in their entirety within the available resources of the Bureau, but 
the hope may be expressed that the lesson of this occasion may make 
so wide an impression that, should the fortune of time offer another 
situation of like significance, the possibilities of the Bureau's service 
may have been so anticipated that a condition of preparedness shall 
have been created. The effective conservation and development of 
the fishery resources is a not unimportant phase of the provision for 
the future welfare of the country. 



Appendix. — The Problem of the Migration of River Herring. 

The following brief account of observations made chiefly during the 
year 1914 are of interest in this connection. While it was not found 
feasible to detail anyone for continuous study of the succession and 
movements of fishes, as would have been desirable, some occasional 
visits could be made, which were not without value. 

The writer visited Keokuk April 15, 1914, when the water was still 
cool, and practically no movement of fishes had occurred. It was 
learned that the river immediately below the dam had remained open 
all the winter, although as a whole below the bridge at Keokuk and 
above the dam it had been frozen over with thick ice. In the exposed 
water the wall-eye or "jack salmon" had been present all the winter 
and fished abundantly with hook and line. Practically the only fish 
then in evidence were perch and crappie in the slues. A few perch 
were noted in the lock, and the lock master stated that a large 
number had been taken at the first locking, about April 10. 

A local informant, Mr. Joe MacAdams, was requested to write me 
of the first appearance of the herring. After a card from him, I 
visited Keokuk again April 29. He stated that the herring first ap- 
peared April 20, and that they became enormously abundant within 
a few days; on the 27th, according to several informants, during a 
warm day, one could at any moment see hundreds of them breaking 
the water in every part of the river below the plant. 

The day of my arrival, April 29, was cold, windy, and cloudy, and 
at first view very few herring were observable. After closer observa- 
tion, however, they were seen to be present in immense numbers, 
and congregated in certain locations exactly as had been predicted. 
(See p. 20 above.) A large number were seen just below the short sec- 
tion of dam between the upper end of the lock and the lower end of the 
power house ; many were observed along the outer wall of the tail-race, 
but in the angle between the power house and the dam and from this 
point to the nearest open spillway, a short distance away, the her- 
ring were fairly massed. Such a close aggregation of fish can rarely 
be seen in fresh water. They had evidently followed up along the 
outer edge of the tail-race until they could go no farther. Again, on 



26 WATER-POWER DEVELOPMENT IN THE MISSISSIPPI. 

the outer side of the last spillway in use, which was about 700 feet 
from the power house, there were considerable numbers of herring. 
From this point to the Illinois shore, a distance of about two-thirds 
of a mile, not a single herring was in evidence. It was evident, there- 
fore, that the herring had been guided by the moving water, so that 
they had in consequence assembled in such remarkable numbers on 
each flank of the stream below the open spillways, many more being 
guided to the eastward side by the strong current from the turbines. 

Opportunity to observe whether they could breast the strong cur- 
rent was favored by the fact that there were three closed spillways 
between three open on the east and nine open on the west ; thus there 
was a triangle of relatively slack water between two strong currents 
which met a short distance below. To the west of the westward 
current fish were abundant; to the east of the eastward current they 
were still more abundant; but in the triangle between not one fish 
could be seen. It was evident, therefore, that the power of the cur- 
rents below the spillways proved an effective barrier to the lateral 
movements of the fish for some distance below the dam; otherwise 
not all of the fish would have been on the right side of one current 
and on the left side of the other. 

The powerful currents caused slight eddies on each side, so that the 
dead water at the foot of the dam on either side was continually 
being drawn into the spillway streams. The fish were also drawn in, 
and it was easily observed that the velocity of the streams made them 
perfectly helpless. As soon as they passed into this stream they were 
thrown up in the foam and spray and often hurled 20 feet or more, 
back, sides, or under parts up, to be carried off as soon as they fell. 
Presumably no injuries were received, as no dead or injured fish were 
observed in the river below. No fish, as previously indicated, were 
drawn in from the slack water between the easterly spillways and the 
westerly, although similar eddies prevailed here. 

It was observed that the roe of the herring was large, and it was 
thought that they would ripen within a few weeks. A visit was made 
by Superintendent Canfield May 29, and a number of herring were 
examined, but they were found to be not quite ready for spawning. A 
later visit was made by Mr. W. B. Gorham, June 11 and 12, when it 
was found that the herring had disappeared. This disappearance had 
not been noticed by the local fishermen for the reason that there were 
present in large numbers the Ohio shad, Alosa ohiensis, which is not 
generally, if ever, distinguished by fishermen from the herring. There 
was no clue, therefore, as to what had become of the herring. Later 
observations at Lake Pepin are mentioned below. 

The gathering of herring in such enormous numbers at Keokuk is 
of particular interest from the fact that this fish has never been gen- 

a Later observations (in August) indicate that the disappearance was only temporary. 



WATEK-POWEK DEVELOPMENT IN THE MISSISSIPPI. 



27 



erally regarded as abundant in the river. Fishermen generally speak 
of it as uncommon, and yet informants sometimes refer to occasions 
when they were taken plentifully about the ends of wing dams. It 
has been supposed, therefore, that the fish is more abundant than 
common observations indicate, but that it migrates rapidly, keeping 
in the current where fishermen work least, and tarrying where the 
water runs swiftly around such obstructions as the wing dams. This 
supposition seemed to receive confirmation from the observations at 
Keokuk in 1913. 

The question still occurred: Would the herring be found in the 
upper river after the dam was constructed ? On the occasion of a 
visit by the writer to Lake Pepin in Minnesota on July 19, 1913, a 
single specimen was taken in a seine haul of our propagation crew. 
Several fishermen were positive that this was the first specimen seen 
in Lake Pepin in that season. The foreman of the crew, Mr. William 
Teachout, was requested to report each subsequent catch, and follow- 
ing is a record of his reports. To check the field identifications, 
specimens were sent to the F airport laboratory from time to time, 
and in each case the identification was confirmed. The seining oper- 
ations were discontinued in Lake Pepin after September 1 1 , though 
pursued in the river below the lake. Later hauls in Lake Pepin 
were made October 17, 18, and 23, without further catch of herring. 

Blue Herring Taken in t Lake Pspin During 1913. 



July 29 8 

Aug. 3 53 

9 1 

12 5 

23 8 

26 12 



Aug. 27. 
Sept. 3. 

5. 

6. 
11. 



3 

25 

5 

26 



The observations at Lake Pepin were continued after the seining 
operations began in Lake Pepin in 1914. A single specimen was 
taken May 12, a few about the middle of June, after which they were 
taken more plentifully, especially in July, as shown by the records 
which follow, covering observations to the date of August 8 : 



Blue Herring Taken in Lake Pepin During 1914. 



May 
June 



Julv 1 . 



14 
3 
] 

12 
5 



July 



Aug. 



9. 
10. 

11. 
20. 
21. 
22. 
23. 
24. 

3. 

7. 



1 

40 
168 

135 

3 

120 

29 

92 

57 

75 

1 



28 WATER-POWER DEVELOPMENT IN THE MISSISSIPPI. 

The fact that the herring became abundant at Lake Pepin shortly- 
after they ceased to be observable at Keokuk suggested that they 
might have passed through the lock. However, the examples 
received from Lake Pepin were noticeably smaller than the examples 
taken at Keokuk. This fact suggested the inference that the Lake 
Pepin herring might not have come from the river below Keokuk, 
but might represent younger fish that had wintered at intermediate 
points or possibly in Lake Cooper. Here the matter must rest pend- 
ing further and more adequate studies. It is noteworthy that the 
herring seem to have appeared in Lake Pepin earlier in 1914 than in 
1913, and that they appeared to be more numerous in the later year, 
notwithstanding that the river was obstructed at Keokuk throughout 
1914 but not in the earlier part of 1913. 

In August, 1914, a number of very young herring were collected 
by Mr. Teachout. In one shipment, August 26, 1914, 21 specimens 
were received of fingerlings or yearling herring, the lengths ranging 
from 122 to 165 millimeters (5 to 6^ inches). On September 5, six 
somewhat smaller specimens were sent us, having lengths of 107 to 
128 millimeters, the smallest being scarcely over 4 inches. Such 
specimens are of particular interest as the first young herring observed 
at our laboratory and as indicating that Lake Pepin is a place where 
the herring breed. Mr. H. W. Clark, who has examined these speci- 
mens, reports that even many of these small herring are infected 
with glochidia of mussels. 

o 



U. S. B. F.— Doc. 805 



Plate II. 




5 .2 



U. S. B. F.— Doc. 805 



Plate III. 




U. S. B. F.— Doc. 805 



Plate IV. 




CONDITION BELOW THE DAM WITH SIX SPILLWAYS OPEN. NORMALLY A MUCH GREATER 
NUMBER OF SPILLWAYS ARE IN USE. 

On the outer side of the first and last spillways of such a group an eddy draws into the spill- 
way streams a portion of the slack water "at base of dam. (See observations described in 
Appendix, p. 26.) 



U. S. B. F.— Doc. 805. 



Plate V. 




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U. S. B. F.— Doc. 805. 



Plate VI. 




